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authorSteven Toth <stoth@kernellabs.com>2010-07-31 15:10:52 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-10-21 07:54:52 -0200
commit58acca1056434dbbbcb3f1aacd759f1039a3169d (patch)
tree66661f935aae0ca46a6cba3a7daf2280acf7bd4c /drivers/media/video/saa7164/saa7164-encoder.c
parent66e1d37884eb43214292ed433fcffb72692c4838 (diff)
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[media] saa7164: measure via histograms various irq and queue latencies
saa7164: measure via histograms various irq and queue latencies Attempting to determine where buffering issues under high load are due to highly latent irq or work queue handling. Signed-off-by: Steven Toth <stoth@kernellabs.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/saa7164/saa7164-encoder.c')
-rw-r--r--drivers/media/video/saa7164/saa7164-encoder.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/media/video/saa7164/saa7164-encoder.c b/drivers/media/video/saa7164/saa7164-encoder.c
index e340a6e..5f73ced 100644
--- a/drivers/media/video/saa7164/saa7164-encoder.c
+++ b/drivers/media/video/saa7164/saa7164-encoder.c
@@ -1030,6 +1030,14 @@ static ssize_t fops_read(struct file *file, char __user *buffer,
int rem, cnt;
u8 *p;
+ port->last_read_msecs_diff = port->last_read_msecs;
+ port->last_read_msecs = jiffies_to_msecs(jiffies);
+ port->last_read_msecs_diff = port->last_read_msecs -
+ port->last_read_msecs_diff;
+
+ saa7164_histogram_update(&port->read_interval,
+ port->last_read_msecs_diff);
+
if (*pos)
return -ESPIPE;
@@ -1114,6 +1122,14 @@ static unsigned int fops_poll(struct file *file, poll_table *wait)
struct saa7164_user_buffer *ubuf;
unsigned int mask = 0;
+ port->last_poll_msecs_diff = port->last_poll_msecs;
+ port->last_poll_msecs = jiffies_to_msecs(jiffies);
+ port->last_poll_msecs_diff = port->last_poll_msecs -
+ port->last_poll_msecs_diff;
+
+ saa7164_histogram_update(&port->poll_interval,
+ port->last_poll_msecs_diff);
+
if (!video_is_registered(port->v4l_device)) {
return -EIO;
}